docs: def validate(token):
      """Validate token and return auth context."""
      token_url = TOKEN_URL_FMT.format(token=token)
      headers = {
          'x-auth-token': token,
          'accept': 'application/json',
      }
      resp = requests.get(token_url, headers=headers)
  
      if not resp.status_code == 200:
          raise HTTPError(status=401)
      return resp.json()